1. Field of the Invention
The present invention relates to an electronic flash apparatus for repeatedly flashing.
2. Related Background Art
An electric flash apparatus has been known which repeatedly flashes by rapidly and repeatedly discharging electricity stored in a condensor to a flash tube during one exposure operation of a camera. The luminous amount of each of the repeated flashes has been determined independently of the voltage accumulated in the condenser.
Generally, in said electronic flash apparatus, a ready-light is turned on when the voltage accumulated in the condenser reaches a predetermined value in order to inform the user that the condenser is charged with said predetermined voltage (the ready-light-ON voltage). This ready-light-ON voltage is fixed to a constant voltage, whether repetitive flash operation is carried out or normal flash operation (single flash operation) is performed.
The above-mentioned ready-light-ON voltage is generally set to be lower than the full-charge voltage. In case of single flash operation, if the single flash operation is fully executed immediately after the ready light is turned on, the luminous amount decreases by only about 1 EV in comparison with the luminous amount in case of single flash operation fully executed after the accumulated voltage reaches the full-charge voltage. The decrease is within an allowable range with respect to photographic sensitivity of film, and accordingly, does not cause any trouble to the photographer.
In case of repetitive flash operation, however, if the operation is executed immediately after the ready light is turned on, duration of the repetitive flash operation becomes shorter than the duration of repetitive operation executed after the accumulated voltage reaches the full-charge voltage. For, in said case, the accumulated voltage is lower than the full-charge voltage, when the flash operation can not be performed at the end of the duration thereof.